MEMS (Microelectromechanical Systems) are electromechanical and microelectronics components in a single device. For example, RF MEMS switches can combine the advantages of traditional electromechanical switches (low insertion loss, high isolation, extremely high linearity) with those of solid-state switches (low power consumption, low mass, long lifetime). RF-MEMS switches furthermore have the advantage of having the possibility for low-cost integration on a variety of substrates, including substrates bearing active semiconductor devices.
One type of RF MEMS device is an adjustable capacitor constructed from two conductive plates—one on the surface of a substrate and the other suspended a short distance above it. Capacitive RF MEMS switches suffer from two main reliability problems. One of these is charge injection in the dielectric as a result of high electric fields. The second problem is degradation or deformation of the membrane or springs of the switch as a result of high speed impact.